Coronavirus cases in people in their 50s surged by 92% last week raising concerns as the government battles to stem infections before winter arrives.
Until Friday, new infections had predominantly been increasing among under-25s, which was less worrying as they are statistically at a lower risk of severe health complications if they contract the virus.
But new Public Health England figures seen by the Telegraph shows that infections among people aged 50 to 59 surged by 92% last week, by 72% among those in their 60s and 44% among those aged 80 or above.
There were 1,635 new Covid-19 cases recorded among people aged 50 and over in the last week, compared with 915 in the previous seven days.